German digital forensic experts on Friday said they had identified over 1,600 suspects from Germany, the US, Switzerland, Austria and France who took part in online chat groups where material including images of sex with minors and with animals was distributed.

Most of the suspects were from across Germany, police leading the investigation in Bavaria said on Friday. The suspects were being evaluated as part of "two large-scale trials" being prepared by police and prosecutors. 

"The distribution of child and adolescent pornography has increased markedly in recent years and is an area of focus for us in many investigations," the deputy head of criminal police investigations in Amberg, Peter Krämer, said.

"As well as people with pedophile tendencies, it is often children and adolescents who share material like this in group chats without thinking, and who therefore regularly open themselves up to criminal prosecution," he warned. 

Those convicted, including minors, would face a prison term of "not less than a year," police said in the statement.

The Bavarian investigators also warned that simply being a member of a group chat, and therefore nominally having a copy of a photo or video stored on your phone that was actually shared by someone else, can suffice for prosecution in Germany.

"That is why our appeal is particularly aimed at parents to sensitize their children to this issue," Krämer concluded.  

What more do we know so far?

Police officers in the Bavarian town of Amberg were first alerted about the online chats after spotting an advertisement earlier in March.

They featured graphic videos and images of sex acts with children, young people and animals.

To give an idea of the scope of the investigation, Amberg police said that information on the suspects covered "several hundred thousand" pages, delivered to their offices in "21 large moving boxes." 

German authorities have clamped down on child sex abuse images online this year with four people being arrested during a huge raid on a dark web club that had 400,000 users. Prosecutors and police have new legal powers designed to help them better pursue such criminality online.

jc/msh (dpa)